Blank feeding and folding apparatus



1 A. WINKLER ETAL BLANK FEEDING AND FOLDING APPARATUS Filed Sept. 22,1930 mnswro nab/en A TTORNEY.

Patented Dec. 1, 1931 UNITED STATES PATENT @FFEQE ALFRED WINKLEB AND MAXDUNNEBIEB, OF NEUWIED-ON-THF-RHINE, GERMANY BLANK FEEDING AN D FOLDINGAPPARATUS Application filed September 82, 1980, Serial No. 483,528. andin Germany September 28, 1929.

This invention relates to envelope machines, and more particularly to ablank folding and 'ng mechanism therefor wherein the bottom sheet of astack of blanks is successively fed by rollers revolving against eachother and adapted for engaging the blank to draw it into the machinewith a single fold.

In feeding apparatus of this character the bottom blanks of the stacksag downward into the space above the point of contact of the rollers;the tendency to sag increasing proportionately to the thinness of thepaper stock of which the blanks are formed, so that frequently two ormore blanks are drawn into the machine at one time.

It is the principal object of this invention.

to provide apparatus of the character wherein sagging of the blanks isavoided and positive feed of onl one blank at a time assured.

In accomplis ing these and other objects of the invention, we haveprovided improved details of structure, the preferred forms of which areillustrated in the accompanying drawings, wherein:

Fig. 1 is a cross sectional view through blank feeding and foldingapparatus equipped with our invention.

Fig. 2 is a plan view of the blank feeding rollers, illustrating a stackof blanks supported thereabove.

- Referring more in detail to the drawings: 1 designates a preferablyinclined late for supporting a stack of blanks 2 whic are positionedthereon by posts 3 engaging the sides of the stack. Formed in the plateis a rectangular opening 4 through which the blanks are successivelydrawn for delivery into the machine. Rotatably mounted in the frame 5 ofthe machine and positioned in the opening 4 is an indrawing roller 6adapted for withdrawing the bottom blank from the stack, and cooperatingtherewith is a counter roller 7. The peripheral surfaces of the rollersthus described are spaced slight 1y from the top surface of the plate 1and the outer sides of the rollers are received in concave recesses 8and 9 formed in the ed the plate opening, so that the efi'ective widththe opening is reduced to a minimum diges of mension to in itself reducetendency of the blanks to sag.

The indrawing roller 6 is preferably tubular and is provided with aplurality of openings 10 covering substantially one-quarter of itscircumference and throu h which a vacuum is formed by a suita 1e pump(not shown).

The counter roller is retained in yielding contact with the indrawingroller and the rollers are operated by suitable gearing, so that uponveach revolution of the indrawing roller the openings 10 come intoreceiving position with relation to the stack and the vacuum drawnthrough the openings sucks the bottom blank downwardly in a trou hshapeand into contact with the counter rol er which cooperates therewith tofold the blank and feed it through spaced guides 11 and 12 into theforwarding rollers 13 and 14 of the machine.

In order that the blank may be readily withdrawn from the feedingrollers the indrawing roller is formed with a segmental recess 15 whichfreely receives the blank as soon as the forwarding rollers en age it,thereby releasing the blank for ready withdrawa into the machine.

As above stated the bottom blanks have a tendency to sag in the space 16formed below the stack above the feeding rollers, and to obviate thisobjectional feature we rovide the supportv and means for separating theblanks as now described.

Fixed'at the lower ends of rods 17 and 18 at each side of the stack ofblanks are con-' duits 19 and 20, respectively, leading-from acompressed air supply (not showng, and which are provided attheir freeen s with nozzles 21 and 22 directed under the blanks and into the space16 formed by the bottom of the blanks and the upper peripheral surfaceof the feeding rollers, whereby air on p der pressure may be disehar edinto the 7 space for efiecting support an retention of 95 the bottomblanks during withdrawal of a blank by the rollers 6 and 7.

In instances where two or more sheets tend to stick together they areinstantly separated by the air jets blowing against the edges of theblanks as they are cupped downwardly across the paths of the jets whichdrive the bottom blanks downwardly and the u per blanks a ainst thebottom of the stack to old them bac In order that the nozzles may beproperly positioned so that the jets are directed in desirable relationwith the ed es of the blanks, the supports are adjustably mounted inbrackets 23 and 24 by set screws as at 25, whereby the nozzles may bepositioned rela tive to the feeding rollers and the bottom of the stack.

From the foregoing it is apparent that the blanks are in effect su ortedby the air 'ets but that the bottom blbnk may be re ily separated fromthe stack by the ets to insure withdrawal of a single blank at a time.Also it is apparent that the air ressure within the space 16 fills outthe blan after it has been cupped by the indrawing roller to materiallyassist in its orderly entrance between the rollers.

What we claim and desire to secure by Letters Patent is:

1. In combination, a blank feeding apparatus including a support for astack of blanks, means for drawing blanks from the bottom of the stack,and means for directing an air jet across the bottom of the stack andadjacent the edges of a blank being drawn from the stack to assist inseparation of the blank from the stack and to support the other blanksin the stack from sagging into the blank drawing means.

2. In combination with a blank feeding apparatus including a plate forsupporting a stack of blanks and having a delivery opening therein, aair of rollers associated with the plate and a apted for withdrawingblanks through the opening from the bottom of the stack, and means ordirecting an air jet between the stack and longitudinally of the rollersfor preventing sagging of the blanks retained in' the stack and to fillout a blank bein removed against said rollers during operation of thesald rollers.

3. In combination with blank feedin apparatus including a plate .torsupporting a stack of blanks and having a delivery opening therein, aair of rollers associated with the plate and a apted for withdrawingblanks through the opening, and air discharge nozzles for directing anair jet between the stack and the rollers for preventing sagging of theblanks retained in the stack during operation of the said rollers.

, 4. In combination with blank feeding apparatus including a plate forsupportlng a stack of blanks and having a delivery opening therein, aair of rollers associated with the plate an adapted for withdrawingblanks through the opening, nozzles for directing air jets between thestack and the rollers for preventing sagging of the blanks retained inthe stack during operation of said rollers, and means for ad usting thenozzles to position the air flow.

5. In combination with a blank feeding apparatus, a support for a stackof blanks, a pair of rota members associated with the support to witdraw a blank from the stack and effect an initial fold therebetween,means for directi an air jet across the stack and between sai rotarymembers to prevent saggin of the blanks in the stack and to fill out thelank being withdrawn against the rotary members to ald in its orderlyentrance between said members to form the fold.

6. In combination with a blank feedin apparatus, a sup ort for a stackof blan s, a pair of rollers or removin blanks from the stack and havinglon 'tudinal contact with each other to effect a old of the blank beingremoved from the stack, and air discharge nozzles positioned in the sace formed above the line of contact of said rollers for preventingsagging of the blanks in the stack durin removal of the blank to fillout the blank eing removed against said rollers.

In testimony whereof we afiix our signatures.

ALFRED WINKLER. ,MAX DUNNEBIER.

